Exploring built environment impacts on transit use – an updated meta-analysis

ABSTRACT

The built environment (BE) is widely accepted to influence transit use (TU). Evidence to date suggests the relationship is dependent on many factors which can be difficult to account for in quantitative studies. This creates barriers to transferring research into practice. Considering many studies together can be useful for accounting for more of the factors impacting transit use. Yet, meta-analysis of research measuring these influences was last undertaken in 2010 based on 18 studies. Since then 90 new quantitative studies have been published. These recent studies use improved methodologies and are conducted in more diverse geographies. This paper reports an improved and updated meta-analysis of built environment impacts on transit use. It compares elasticity estimates from research published pre-and post-2010 and explores the impact of new methods and a more diverse geographical representation on findings. Updated meta-elasticities range from <0.01 to 0.26; a similar range to the 2010 study. However, at the individual indicator levels, more recent results are different. Elasticities for urban density, including population, employment and commercial density, have increased significantly in studies published since 2010, as did that of land use mix. However, measures of local access, design and jobs-housing balance decreased in post-2010 studies. These results confirm the small but imprecise relationship between the BE and TU. Results also suggest that while the range of elasticity impacts is relatively consistent, new study methodologies, notably those that control for regional accessibility and self-selection, and the increasing geographical diversity in study applications, is acting to change BE-TU findings at the indicator level. Research setting and context are important to consider when using empirical results to design BE strategies to promote transit use.     

Required traffic micro‐simulation runs for reliable multivariate performance estimates

Previous methods to calculate the minimum number of traffic micro‐simulation runs do not consider multiple measures of performance simultaneously at an overall confidence level, which can lead to unreliable simulation outputs. This paper describes new methodologies for calculating the minimum number of traffic micro‐simulation runs for multivariate estimates at an overall confidence level. Simultaneous confidence intervals obtained from multiple comparisons in statistical theory such as the Bonferroni inequality and simultaneous confidence interval method are used to estimate multiple measures of performance with allowable errors at an overall confidence level. Measures of performance can be means and standard deviations. Results of numerical analysis based on an example corridor suggest that the proposed methods provide improved means of assessing statistical accuracy of multiple measures of performance. Results also indicate that the minimum number of runs is influenced by not only the sample size issue but also the complexity of the traffic system. Copyright © 2015 John Wiley & Sons, Ltd.     

A disaggregate study of urban rail transit feeder transfer penalties including weather effects

Transfers between urban rail transit (URT) and its feeder modes represent a considerable barrier to its ridership and the network-wide usage of public transit. The aim of this research is to quantify the time-independent transfer penalty between URT system and feeder modes and to explore its variability by different factors. Based on Melbourne URT origin and destination survey data, this study focused on URT access and egress journeys and estimated URT feeder transfer penalties by formulating feeder mode choice models. With three-hourly weather data and demographical data introduced, this paper conducted disaggregate analyses to investigate the variability of URT feeder transfer penalty across weather conditions, trip types and individual characteristics. According to the model estimation results, the values of transfer penalty vary according to the direction of transfer and the preference ordering for different transfer combinations is URT-tram, URT-bus, tram-URT, bus-URT and auto-URT. It found that local weather elements in terms of air temperature and precipitation are significant factors resulting in the variability of the transfer perception by URT travellers. Transfer penalties for access journeys increase with the rise of air temperature. The non-linear effects of precipitation on URT feeder transfer penalties were observed. In addition, commuters perceive smaller transfer penalties than other travellers for all of the transfer combinations except for bus-URT transfers. Travelers from remote areas perceive smaller transfer penalties for access trips. Travellers’ loyalty to public transit restrains transfer penalties. The male travellers perceive higher transfer penalties than the female. The elderly travellers impose low transfer penalties to access journeys but high transfer penalties for egress journeys. Finally, the paper explored policy implications and details areas for future research.     

Investigating links between transport disadvantage, social exclusion and well-being in Melbourne - Updated results

This paper updates results of an international study aimed at quantifying the links between transport disadvantage (TD), social exclusion (SE) and well-being (WB) in Melbourne, Australia. The study extends knowledge associated with SE and transport by quantify social and behavioural implications of lack of public and private transport and the nature of the social WB benefits associated with improving services.Study aims and methodology are outlined. Recent findings covered relate to car ownership on the urban fringe, patterns of transport disadvantage, the analysis of time poverty related to transport disadvantage, measuring the economic value of additional mobility and use of a Structural Equation Model (SEM) to relate WB and SE to TD and a series of explanatory factors.Overall results suggest that those without a car on the urban fringe adjust well with their circumstances by living close to activity centres. They demonstrate sustainable choices, trading off budgets and home location to balance mobility and accessibility. Poorer households with high car ownership value mobility and cheaper more remote fringe dwellings but demonstrate numerous strategies to reduce high car costs which are acknowledged as a significant burden. Analysis identifies 4 key types of transport disadvantage including a ‘vulnerable/impaired’ group which should be of much greater concern for targeted policy than others due to poor scoring on SE and WB scales. The economic value of new mobility is also explored with results suggesting $AUD 20 per average new trip which is four times larger than conventional values for generated travel.Analysis has also suggested that transport disadvantage can relate to socially advantaged as well as socially disadvantaged groups through time poverty. This was found to be an important mitigating factor when relating TD to WB. A statistically reliable structural equation model is developed suggesting the SE-WB link is strong (−.87) with a modest link between TD-SE (.27).Areas for future research in the project are also summarised.     

大型国际活动交通组织规划方法综述

探讨夏季奥运会采用的交通组织规划方法,同时总结世界上最大规模的特殊活动——沙特阿拉伯麦加朝觐/副朝交通组织规划经验。每年一度的麦加朝觐已经延续几个世纪,在最近几十年人数持续增长,朝圣者已增至600万人,包括朝觐一周内300万人和斋月期间100万人。目前,这项活动是历史上规模最大且定期举行的特殊活动,其规模预计还将大幅增长。奥运会是世界上第二大特殊活动,每4年举办一次,在主办城市持续2周。通常奥运会主办城市自身的交通压力已经非常巨大,在奥运会期间同时还要额外满足4万名奥运官员和运动员以及800万名观众的出行需求。因此,奥运会交通组织规划对于保障赛事顺利开展至关重要。通过描述这两项活动的背景和交通供需特征,概述已有交通组织规划方法,旨在分析和总结大型活动交通组织规划的经验教训,探讨可供选择的规划策略。     

Learning to use transit services: adapting to unfamiliar transit travel

Transportation - Travel behavior change has become an area of interest in many cities around the world, particularly to encourage people to change from car use to transit use. Previous research...     

Predicting the collapse of externally pressurised ring-stiffened cylinders using finite element analysis

This paper describes the application of finite element (FE) analysis to the prediction of the non-linear elasto-plastic collapse of ring-stiffened cylinders under hydrostatic loading. A range of legacy experimental test models have been analysed using FE idealisations generated using measured as-built shape data including out-of-circularity (OOC), frame alignment and tilt and other scantlings. The FE models also explicitly included the residual stresses caused by cold bending. Short and long ring-stiffened cylinders, which were designed to isolate interframe and overall collapse modes, respectively, were considered as were some intermediate length cylinders where the possibility of interactive collapse was also present. In general, the collapse pressures were predicted to within 6%. However, for some of the interframe collapse models, it was necessary to use the minimum measured plate thickness to achieve this. This was largely attributable to the limited measured plate thickness data.     

Estimating the agglomeration benefits of transport investments: some tests for stability

The case for including agglomeration benefits within transport appraisal rests on an assumed causality between access to economic mass and productivity. Such causality is justified by the theory of agglomeration, but is difficult to establish empirically because estimates may be subject to sources of bias from endogeneity and confounding. The paper shows that conventional panel methods used to address these problems are unreliable due to the highly persistent nature of accessibility measures. Adopting an alternative approach, by applying semiparametric techniques to restricted sub-samples of the data, we find considerable nonlinearity in the relationship between accessibility and productivity with no positive effect to be discerned over broad ranges of the data. A key conclusion is that we are unable to distinguish the role of accessibility from other potential explanations for productivity increases. For transport appraisal, this implies that the use of conventional point elasticity estimates could be highly misleading.     

Optimizing location and capacity of rail-based Park-and-Ride sites to increase public transport usage

This paper presents a new methodology to identify optimal locations and capacity for rail-based Park-and-Ride (P&R) sites to increase public transport mode share. P&R is usually taken as an important component of policies for the sustainable development of urban transport systems. However, previous studies reveal that arbitrarily determined P&R sites may act to reduce public transport commuting. This paper proposes a methodology for the optimal location and capacity design of P&R sites, with the aim of enhancing public transport usage. A Combined Mode Split and Traffic Assignment (CMSTA) model is proposed for the P&R scheme. Taking the CMSTA model as the lower level, a bi-level mathematical programming model is then built to establish the optimal location and capacity of P&R sites. A heuristic genetic algorithm is adopted to solve this model. Finally, a network example is adopted to test numerically the proposed models and algorithms.     

A new approach to evaluating on-road public transport priority projects: balancing the demand for limited road-space

Despite widespread growth in on-road public transport priority schemes, road management authorities have few tools to evaluate the impacts of these schemes on all road users. This paper describes a methodology developed in Melbourne, Australia to assist the road management authority, VicRoads, evaluate trade-offs in the use of its limited road-space for new bus and tram priority projects. The approach employs traffic micro-simulation modelling to assess road-space re-allocation impacts, travel behaviour modelling to assess changes in travel patterns and a social cost benefit framework to evaluate impacts. The evaluation considers a comprehensive range of impacts including the environmental benefits of improved public transport services. Impacts on public transport reliability improvements are also considered. Although improved bus and tram reliability is a major rationale for traffic priority its use in previous evaluations is rare. The paper critiques previous approaches, describes the proposed method and explores some of the results found in its application. A major finding is that despite a more comprehensive approach to measuring the benefits of bus and tram priority, road-space reallocation is difficult to economically justify in road networks where public transport usage is low and car usage high. Strategies involving the balanced deployment of bus and tram priority measures where the allocation of time and space to PT minimises negative traffic impacts is shown to improve the overall management of road-space. A discussion of the approach is also provided including suggestions for further methodology development.